According to the report, the contractors were employed by the Spear Operations Group LLC, a company registered in Delaware, and founded by "Abraham Golan, a charismatic Hungarian Israeli security contractor who lives outside of Pittsburgh.”

In interviews with BuzzFeed, Golan referred to the mission as “a targeted assassination program in Yemen,” adding that “I was running it. We did it. It was sanctioned by the UAE within the coalition.”

In 2015, contractors with the group led by Golan, allegedly attempted to assassinate Anssaf Ali Mayo, the leader of an Islamist political party in Yemen. Until now it was unknown that the mission was carried out by U.S. mercenaries.

Of the mercenaries with the group, one was a former member of the CIA, another was a Special Forces sergeant with the Maryland Army National Guard, and two were former Navy SEALs, one of whom was reportedly in the reserves and a veteran of SEAL Team 6, according to BuzzFeed. The remaining members were largely former French Foreign Legionnaires, BuzzFeed reports.

Golan, the founder of the group, claimed to have been educated in France, to have served in the French Foreign Legion, and to have fought oversees — though his background and military service could not be verified by BuzzFeed, although sources familiar with him told the news site that he was “prone to exaggeration,” but “for crazy shit he’s the kind of guy you hire.”

The CIA reportedly had no information about Spear Operations Group's missions in Yemen, and the Navy Special Warfare Command declined to comment for the BuzzFeed report. However the news organization spoke with a former official who previously worked in the UAE, and initially said there was no way Americans would be permitted to participate in such programs, only to call back and say: "There were guys that were basically doing what you said," adding that the mercenaries were “almost like a murder squad,” BuzzFeed reported.

The legal ramifications of the alleged program are unclear. It's illegal under U.S. law to “conspire to kill, kidnap, maim” someone in another country, and companies that provide military services to foreign nations are regulated by the State Department, which told BuzzFeed that it has "never granted any company the authority to supply combat troops or mercenaries to another country."

Yet the rules don't explicitly ban mercenaries — evidenced by the scores of Americans serving overseas alongside foreign militaries with little legal consequence. Spear Operations Group reportedly arranged for the UAE to bestow military rank to the Americans involved in operations in Yemen, which could provide legal protection.